a few things i learned by this build by master-style use.
1. At the AP Argus its a flat bottom, that would supported strength to the tail, more than rounded foam who was pressed many times to achive its design. Its essential with internal support all the way to tail!!.
When see first picture of the internal, this is short behind last form.. I did plan to put my servos in back as on the Argus, and even cutted the internal spear even more.... well lesson learned, servos goes into the hatch, and internal structure to give better stiffness of tail is done.
2. put pushrods at place when you can see where it should go!!! I needed cut a hole in bottom AGAIN (after done it before to strenghten the tailsection, and forgot about pushrods before glued shut ..) , to find the hole in the second form it should go trough...
tip: on every tip of rudder, ailerons , elevator, i remove a part of the foam between the two papersheets outside (3 - 10mm) fill in Gorilla glue and press the two papersheets shut at edge in the shape i want, tape and let dry. Then i get strenghten edges, and aerodynamic shape.
By making the wings detachable. it needed more support in fuselage.. aka more weight, sad enough... still needed!!. Also both wings have strong supports internal.